一种非调质钢组织转变及性能的研究

Study on Microstructure Transformation and Properties of a Non-quenched and Tempered Steel

一种非调质钢在Gleeble 3800热模拟机上进行试验,测定了该非调质钢在不同冷却速度下膨胀曲线,同时结合金相-硬度法获得了该非调质钢的连续冷却转变时静态CCT曲线、显微组织和维氏硬度,以及等温转变时显微组织和维氏硬度。奥氏体在连续冷却速度分别为0.1、0.5、1℃/s以及在560℃等温转变前后的连续冷却速度为2℃/s,等温时间分别为10、20 min时,转变组织为铁素体+珠光体;奥氏体在560℃等温转变前后的连续冷却速度分别为3、4℃/s,等温时间分别为10、20 min时,转变组织为铁素体+珠光体+微量或少量贝氏体。本研究结果,对下游用户使用圆钢锻造成零件后,获得铁素体+珠光体组织或铁素体+珠光体+微量或少量贝氏体组织的冷却工艺提供了参考。

A non-quenched and tempered steel has been tested with Gleeble 3800 thermal simulator to measure the expansion curve at different cooling speeds.The static CCT curve,microstructure and Vickers hardness under continuous cooling have been gained by combining with metallographic-hardness method.When the continuous cooling speed of respectively is 0.1,0.5,1℃/s,and the continuous cooling speed is 2℃/s,before and after isothermal transformation at 560℃and the isothermal time is 10 and 20 min respectively,the austenite transform into ferrite+pearlite.When before and after isothermal transformation at 560℃,the continuous cooling speed is 3℃/s and 4℃/s respectively and the isothermal time is 10 and 20 min respectively,the changed structure of austenite is ferrite+pearlite+trace or a small amount of bainite.The study results provide a reference for the cooling process of ferrite+pearlite or ferrite+pearlite+trace or a small amount of bainite after forging the parts with round steel for the downstream user.